The invention of this application relates to dispensing a liquid sample and distributing the sample on a surface.
1. Field of the Invention
The present invention has particular application to the medical and laboratory diagnostic fields. In these fields, it is often necessary to dispense liquids from conventional containers, such as test tubes, onto a surface, and then distribute the dispensed liquid on the surface. Because the distributing operation can be dangerous if performed with substances that are hazardous, toxic, or infectious, the invention is further related to the field of laboratory and worker safety.
2. Description of the Related Art
The invention is generally related to the following United States patents dealing with dispensing liquids from a container, the disclosures of which are hereby incorporated by reference: U.S. Pat. No. 4,811,866, Golias, issued Mar. 14, 1989; U.S. Pat. No. 4,925,065, Golias, issued May 15, 1990; U.S. Pat. No. 5,114,033, Golias et al, issued May 19, 1992; and U.S. Pat. No. 5,139,174, Golias, issued Aug. 18, 1992.
Other patents in the prior art include the following: U.S. Pat. No. 3,366,278, to Fobes, issued on Jan. 30, 1968; U.S. Pat. No. 3,788,528, to Ogle, issued on Jan. 29, 1974; U.S. Pat. No. 4,411,661, to Kersten, issued on Oct. 25, 1983; U.S. Pat. No. 5,024,355, to Jouillat et al, issued on Jun. 18, 1991; U.S. Pat. No. 5,086,950, to Crossdale et al, issued on Feb. 11, 1992; U.S. Pat. No. 5,163,583, to Whitworth, issued on Nov. 17, 1992; and U.S. Pat. No. 5,286,453, to Pope, issued on Feb. 15, 1994.
A task often performed in the chemical and biological field is the dispensing of liquid samples from sealed or unsealed containers, such as test tubes and vacuum tubes. As disclosed in U.S. Pat. No. 5,286,453, issued Feb. 15, 1994 to Pope, it is often necessary to isolate the liquid sample from the laboratory technician for safety reasons, such as where the sample is a hazardous, toxic, or infectious substance. Another reason to isolate the sample from the technician is to prevent contamination of the sample.
As further disclosed in the '453 patent, certain tests require the technician to spread a liquid sample on a glass slide. For example, a proper spread or blood distribution is an important hematologic procedure that is required to perform many hematologic diagnoses.
Smearing may be accomplished by a number of prior art techniques, many of which involve a technician's handling of the glass slide containing the sample. One technique of the prior art is for a laboratory technician to wipe a “clean” glass slide together with the slide containing the sample which “smears” the sample on each. This smearing technique can jeopardize both the health of the lab technician and the purity of the sample being smeared. Where the sample is a hazardous substance, the technician must take great care to properly rub the two glass slides together. The slides must not puncture the technician's skin or any protective gloves or coverings which the technician is wearing. Further, the sample must not rub off onto the technician, where it could be contacted or transmitted in the future.
Undesirable contamination of the sample is a problematic characteristic of this prior art technique because it is difficult to isolate each “clean” glass slide from foreign substances.
Another disadvantage of this prior art smearing technique is that it is inefficient and time consuming. The technician is unable to quickly dispense and smear samples because both hands must be used in the smearing step. Thus, the dispensing container must be placed aside by the technician while the smearing step is performed. Therefore, it is difficult to rapidly dispense and smear many samples consecutively.
The '453 patent, previously discussed, discloses a device for dispensing liquid, such as blood, onto a glass slide. The dispensing device disclosed in the '453 patent is undesirable because, while it attempts to address the step of dispensing hazardous blood onto a glass slide, it does not address the step of smearing the hazardous blood onto the slide. The techniques of the prior art must be used with the device of the '453 patent to smear the dispensed blood on the slide, consequently resulting in the problems previously described concerning technician safety, sample contamination, and inefficiency.
What is needed is a method of dispensing and distributing hazardous samples onto a surface, without exposing the technician to the hazardous sample.
What is needed is a method of dispensing and distributing samples onto a surface without contaminating the samples.
What is needed is a efficient method of dispensing and smearing samples onto a surface so that numerous dispense-smear steps can be performed in sequence.